Political Mystery Tour The first journalist to review the first climate-change opera, Robert Butler finds And While London Burns to be 'highly imaginative, serious and timely.'

You're sitting at a table in Starbucks in the City of London when a female voice whispers into your ear, "Hello. I'm your guide. Follow me."

It turns out this seductive guide has a very specific tour in mind. "I will take you to fund managers, banks, insurance companies, lawyers, advertising agencies and recruitment agencies ..."

And While London Burns

The Guide is one of the three main characters in a remarkable audio opera And While London Burns. The opera is composed by Isa Saurez and has a libretto by John Jordan and James Marriott. To listen to it, go to the Platform / And While London Burns website, download the sound file to an MP3 player, and make your way to the lower ground floor of Starbucks at 1, Poultry, EC2R 8EJ.

From a table there, you will follow an hour-long route round the city. You may only ever be a few hundred yards from Bank tube station, but the opera will take in Azerbaijan, Bangladesh, the Niger Delta, Algeria, Iraq, Siberia and the Gulf of Mexico.

The guide (Josephine Borradaile) coaxes you up the escalator, along the pavement, and across the road. "See the little birch tree there ... turn left."

The pink building, you soon learn, is Morley Fund Management, which has £165 billion to invest. Yes, that's billion pounds. It holds 2.1% of all BP's shares. The building opposite, next to the Roman ruins, is the Sumitomo Mitsui Banking Corporation. It has provided a loan of $143 million for BP's massive gas scheme in West Papua. As you stand in the shadow of these prestigious offices, a children's choir sings in your ear about a warming world.

The opera's central character, never named, is a fund manager in his 40s, played with fierce, edgy intensity by Douglas Hodge. A frayed exhausted figure, his journey through the city relives the end of his love affair with a climate scientist, Lucy (Deborah Stoddart). It also charts his growing despair at the short-sightedness of his work in the city.

The first pleasure in following And While London Burns is the serendipitous one of surrender. Nearly everyone else in the city at lunchtime is hurrying purposefully from office to sandwich bar and back. But you are a tourist, cut free from those pressures, with no idea where you are about to go, and with only some voices as a lifeline.

The second pleasure is one of discovery. "See the gap in the black marble wall on your right," says the Guide, "Step into it and start climbing the stairs." You head down corridors, peer into buildings, and find out what happens the other side of the tinted windows. The journey becomes a magical mystery tour, a London walk, a political essay, a short story and a requiem.

Gradually, the pieces pull together. As you move from Morley to Sumitomo, from the Royal Exchange to Deutsche Bank, from the Gherkin to the Lloyds building, you hear how money and influence flow from one institution to another.

To give a single example: the chairman of BP sits on the board of the Royal Bank of Scotland and the chairman of the Royal Bank of Scotland sits on the board on BP. (In 2004 RBS loaned BP $100 million dollars to help construct the Baku-Tbilisi-Ceyhan pipeline).

This is what the librettists call 'the carbon web', the intricate pattern of alliances that centres around 'black gold'.

Jordan and Marriott are in no doubt that the same oil industry that builds the skyscrapers and pays the city salaries also threatens communities in the developing world and produces the mountains of exhaust that drives climate change. The bitter irony is that many of the people who know the most about the dangers of climate change are insurers working inside the Gherkin. To meet the insurance claims that arise from the results of climate change, the opera tells us, they are investing in the very things that cause those insurance claims.

And While London Burns offers an intriguing tour of these high-tech buildings, which registers the global effects that flow from decisions that are taken within them. As protest art, it is highly imaginative, serious and timely.

Jordan and Marriott are in no doubt that the same oil industry that builds the skyscrapers and pays the city salaries also threatens communities in the developing world and produces the mountains of exhaust that drives climate change.

The bitter irony is that many of the people who know the most about the dangers of climate change are insurers working inside the Gherkin.